Does a flashlight manufacturer have to warn consumers about the potential of leaking batteries it didn’t produce? Or does an ashtray maker have to flag smokers about the health dangers of tobacco?

Those were questions posed by Supreme Court justices Oct. 10 to manufacturers fighting claims they’re liable for asbestos-containing parts that they didn’t make but are used in their products.

“Why are too many warnings bad?” Justice Brett M. Kavanaugh asked Shay Dvoretzky of Jones Day in Washington.

Dvoretzky...